Initial commit

snippets/netmask2cidr.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+netmask2cidr() { 
+  case $1 in
+      0x*)
+      local hex=${1#0x*} quad=
+      while [ -n "${hex}" ]; do
+        local lastbut2=${hex#??*}
+        quad=${quad}${quad:+.}0x${hex%${lastbut2}*}
+        hex=${lastbut2}
+      done
+      set -- ${quad}
+      ;;
+  esac
+
+  local i= len=
+  local IFS=.
+  for i in $1; do
+    while [ ${i} != "0" ]; do
+      len=$((${len} + ${i} % 2))
+      i=$((${i} >> 1))
+    done
+  done
+
+  echo "${len}"
+}
+
+netmask2cidr $1